Rotary-piston machine

ABSTRACT

A rotary-piston machine ( 10 ) comprising a housing ( 5 ) having a cavity ( 9 ), a rotor ( 2 ) received in the housing ( 5 ), which rotor ( 2 ) having a rotor axis (A) and a peripheral surface ( 21 ), inlet and outlet passages ( 3, 4 ) in communication with said cavity ( 9 ), one or more vanes ( 1 ) radially slideable received in slots ( 11 ) in the rotor ( 2 ), each vane ( 1 ) extending radially from the internal surface ( 20 ) of the housing ( 5 ) to the rotor axis (A), and at least one working chamber ( 9   a ) being part of the cavity ( 9 ) and is defined by the internal surface ( 20 ) of the housing ( 5 ), the peripheral surface ( 21 ) of the rotor ( 2 ) and the side surface of at least one vane ( 1 ). Each vane ( 1 ) is articulated connected about an axis (C) to one end of a control arm ( 7 ) and is in the other end pivotable journalled in a fixed axle shaft ( 8 ) having a central axis (B) being coincident with the axis extending centrally through the cavity ( 9 ) of the housing ( 5 ), which axis (B) extend in parallel with and spaced (d) from the rotor axis (A), and the rotor ( 2 ) proper constitute the unit for power take off or power input.

BACKGROUND OF THE INVENTION

The present invention relates to a rotary-piston machine comprising ahousing having a cavity, a rotor received in the housing, which rotorhas a rotor axis and a peripheral surface, inlet and outlet passages incommunication with said cavity, one or more vanes radially slideablereceived in slots in the rotor, each vane extending radially from theinternal surface of the housing to the rotor axis, and at least oneworking chamber being part of the cavity and is defined by the internalsurface of the housing, the peripheral surface of the rotor and the sidesurface of at least one vane.

The rotary-piston machine is a thermodynamic machine, which by somemodifications can be utilised as combustion engine, heat exchanger,punip, vacuum pump and compressor. The rotary machine can be assembledin several units and in series so that the machine principle is usedboth for the compressor unit and the combustion engine unit in a supercharged engine. It is to be stated this early that the rotary machinehas no crankshaft and that the power supplied to or taken out from themachine is effected directly to or from the rotor.

Prior art combustion engines of the rotary type are embodied as rotarypiston engines. Here is the rotary piston rotating, which piston is inform of a rotor having an arched triangular design, in an annularcylinder bore. Such combustion engines have, in addition to acomplicated design, that disadvantage that the rotor have considerablysealing problems against the cylinder wall. Moreover, these combustionengines have a vast filel consumption.

A prior art combustion engine comprising an engine housing having aworking chamber, which receives a continuously rotatable rotor, andinlet and outlet for combustion gasses, is known from DE-3011399. Therotor is substantially cylindrical and rotates in an ellipticallydesigned cavity, which comprises diametrically opposing combustionchambers defined by the surface of the rotor and the internal surface ofthe cavity. The rotor is designed with radially extending sliding slots,which receive and guide vane pistons that are able to slide radiallyoutwardly and inwardly in the sliding slots. The vanes are articulatedconnected via a connecting rod with a crank pin, which is further a partof a journalled crankshaft. When the rotor is rotating, the piston vanesare moving radially outwardly and inwardly in the sliding slots due tothe fixed support to said crank pin. Thus the one set of vanes will actin the one part of the cavity, i.e. the one combustion chamber, whilethe other set of vanes will act in the diametrically opposite chamber.

U.S. Pat. No. 4,451,219 reveals a rotary steam engine having twochambers and no valves. Also this engine has two sets of rotor bladeswith three blades in each set. Each set of rotor blades is turningaround its own eccentric point on a stationary common crankshaft withinan elliptical engine housing. A rotor of drum type is centrally mountedin the engine housing and defines two diametrically opposing radiallyworking chambers. The two sets of rotor blades are moving substantiallyradially outwardly and inwardly in sliding slots in the rotor inaccordance with the above described engine. The vanes are also here intheir central end supported in an eccentric located shaft stub that isfixed. However, the vanes are not articulated, but are in the oppositeend PivotTable journalled in a bearing provided peripheral in the rotor.

Pumps and compressors of the vane type are also known. U.S. Pat. No.4,451,218 relates to a vane pump having rigid vanes and a rotor that iseccentric supported in the pump housing. The rotor has slots that thevanes pass radially through and are being guided by. On each side of thesliding slots are seals provided.

U.S. Pat. No. 4,385,873 shows a rotary engine of the vane type that canbe used as motor, compressor or pump. This one also has an eccentricmounted rotor tho a number of rigid vanes are passing radially through.

Further examples of the prior art are disclosed in U.S. Pat. No.4,767,295 and U.S. Pat. No. 5,135,372.

SUMMARY OF THE INVENTION

One object with the present invention is to provide a rotary-pistonengine having a high efficiency, low fuel consumption and low emissionsof polluting substances, like carbornonoxide, nitrous gasses and unburnthydrocarbons.

Another object with the present invention is to provide a rotary-pistonmachine of a compact design, i.e. small machine displacement volume andsmall overall volume in respect of power output.

In accordance with the present invention, a rotary-piston machine of thetype described in the introductory part of the specification isprovided, and is distinguished by that each vane is articulatedconnected about an axis to one end of a control arm and is in the otherend pivotally journalled in a fixed axle shaft having a central axisbeing coincident with the axis extending centrally through the cavity ofthe housing, which axis extend in parallel with and is spaced apart fromthe rotor axis, and the rotor proper constitute the unit for power takeoff or power input. The above disclosed embodiment is a cleanrotary-piston machine that can be a compressor or a combustion enginewith or without an external compressor.

Preferably do each vane tip describe a cylinder surface sector havingcentre of curvature in the axis through the joint connecting the vane tothe control arm. The idea of this is that the tip of the vane, along aline extending in parallel with the rotor axis, at any time is to betangent to the internal surface of the cavity, though not touch thesurface. This line will be displaced on the vane tip during rotation ofthe rotor and will at any time describe a cylinder surface which isapproximately similar to the internal surface of the housing with adifference in the tolerance that is present between the tip of the vaneand the internal surface of the housing only. The tolerance between thevane tip and the internal surface of the cavity is to be as small as itis practical possible to make it.

As a particularly favourable embodiment, the arch length of the cylindersurface sector, and thus the thickness of each vane, is determined bygeometric relations, i.e. radius for the cylinder surface sector, thedistance between the central axis of the cavity and the axis through thejoint that connects the vane to the control arm, and the distancebetween the rotor axis and the central axis of the cavity. When thesegeometric conditions are present, an optimum design is obtained causingthat the vane tip at any time is tangent to the internal surface of thecavity during the complete revolution of the rotor, and this embodimentwill be able to work well without use of sealings.

It is to be noted that the thickness of the vane can be larger withoutgetting any effect for the sealing against the internal surface of thecavity. However, if the thickness of the vane is less than the optimum,a tangent of the tip of the vane against the internal surface of thecavity will not be obtained in parts of the revolution of the vane withthe rotor and a sealing on the vane tip will normally be required. Thethinner the vane is in respect of the optimum, the longer will the areathat the vane tip is not tangent to the internal surface of the cavitybe.

In some embodiments it may be suitable to provide sealing means betweenthe tip of the vane and the internal surface of the housing. Preferablyis the sealing means provided on the tip face of the vane and thesealing means is sweeping against the internal surface of the cavity. Insome situations it may also be suitable to provide sealing means betweenthe vane slots in the rotor and at least one side face of the vane.Sealing means can also be provided between the internal surface of thehousing and the peripheral surface of the rotor where the surfaces aretangent to each other, alternatively in the area in which they intersecteach other.

In order to minimise the wear of the vanes and improve the operatinglifetime, sliding bearings can be provided in the slots in the rotor.The sliding bearings may be in form of exchangeable bearing inserts orbe permanently provided to the rotor.

In one embodiment, the peripheral surface of the rotor can intersectinto the internal surface of the housing across a sector and acorresponding recess is then formed in said surface of the enginehousing.

In one embodiment the rotary-piston machine comprises at least onecompressor unit which is co-rotating with the combustion engine unit andhave a design corresponding to the combustion engine unit, i.e. have aseparate cavity, a separate rotor and separate vanes, in addition topassages that connect the respective cavities.

With the object to stabilise the fixed axle shaft in the housing, thefree end of the axle shaft can be supported internally in the rotorproper by means of a custom designed eccentric adapter and a bearing.

One exemplary embodiment of the rotary-piston machine according to theinvention will now be described in closer detail with reference to theaccompanying drawings where:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of one embodiment of a rotary-pistonmachine in form of a combustion engine and two adjacent compressors, oneon each side of the combustion engine, and like it appears when inassembled state,

FIG. 2 shows the rotary-piston machine when one of the end covers islifted off,

FIG. 3 shows the rotary-piston machine according to FIG. 2 when the endbearino is removed,

FIG. 4 shows the rotary-piston machine according to FIG. 3 when anotherpart of the housing is lifted off and more of the rotor appears,

FIG. 5 shows the rotary-piston machine according to FIG. 4 when anotherpart of the housing is lifted off and still more of the rotor appears,

FIG. 6 shows the rotary-piston machine according to FIG. 5 when anotherpart of the housing is lifted off and still more of the rotor appears,

FIG. 7 shows the rotary-piston machine according to FIG. 6 in which oneof the halves of the rotor housing is lifted off and the rotor vane unitclearly appears,

FIG. 8 shows the rotary-piston machine according to FIG. 7 in which alsothe rotor vane unit is lifted off so that the second half of the rotorhousing remain in the housing in is addition to the axle shaft providedeccentric in the housing,

FIG. 9 shows the rotary-piston machine according to FIG. 8, in which thelast part of the rotor is removed,

FIG. 10 shows the rotary-piston machine when another part of the housingis lifted off,

FIG. 11 shows the rotary-piston machine when another part of the housingis lifted off so that only the second end cover do remain together withthe eccentric axle shaft,

FIG. 12 shows the eccentric axle shaft,

FIG. 13 shows the assembled rotor vane unit including three vane parts,

FIG. 14 shows the unit according to FIG. 13 disassembled and theindividual parts so deployed,

FIG. 15 shows the one half of the rotor housing viewed externally,

FIG. 16 shows the same rotor housing half as in FIG. 15, but viewedinternally,

FIG. 17 shows the lower half of the rotor housing viewed internally,

FIG. 18 shows the lower half of the rotor housing viewed extemally,

FIG. 19 shows a principle view of a second embodiment of a rotary-pistonmachine in form of a compressor, or pump, having four vanes according tothe invention.

FIG. 20 shows another embodiment of the rotary-piston machine havingfour vanes in which the peripheral surface of the rotor across a sectorcuts into the internal surface of the housing, according to theinvention,

FIG. 21 shows a principle view of still another embodiment of therotary-piston machine having one vane only, according to the invention,and

FIG. 22 shows the eccentric adapter that supports the rotor eccentric inrespect of the cavity of the housing.

DETAIL DESCRIPTION OF THE DRAWINGS

FIG. 1 shows one embodiment of a rotary-piston machine 10 according tothe invention. However, it is to be noted that this is an embodiment ofthe machine that is assembled of a combustion engine unit and twocompressor units, one on each side of the combustion engine unit, and inwhich all units are co-rotating. Further, it is to be noted that theengine is designed and manufactured with such precision that use ofsealings are kept at a minimum. Use of labyrinth sealings is considered.Further tests will in time reveal this and presumably will at least someapplications work well without sealings and without lubrications, exceptthe bearings, which are sealed and prelubricated. The constructingmaterials can be different steel grades, but also plastics and teflonwill be well suited for some applications.

The rotary-piston machine 10 represents in FIGS. 1-18 a superchargedcombustion engine.

The engine 10 comprises a housing 5 having several internal cylindricsurfaces which surround an eccentric located rotor 2 where the poweroutput part of the rotor 2 is showing on the figure. Note that theengine is omit a crankshaft and the power is taken out directly from therotor 2. The rotor 2 rotates about a rotation axis A. The housing 5 isconstructed of a number of plates having similar thickness and externalconfiguration. The housing 5 may instead be manufactured in two halvesthat are placed against each other. How the housing is beingmanufactured is, however, a choice that has to be taken of a man skilledin the art.

The rotary-piston engine 10 further comprises inlet passages 3 for fueland air mixture and outlet passages 4 for exhaust gases. The individualparts of the housing 5 are kept together by means of bolts extendingthrough holes 13 in each comer of the housing 5. The individual platesthat the housing 5 is constructed of are numbered 5 a to 5 g. Thus theplate 5 a represents the upper end cover and the plate 5 a the lower endcover.

FIG. 2 shows the rotary-piston engine 10 according to FIG. 1, but wherethe upper end cover 5 a is lifted off. By this an upper end bearing 14appears. Internally of the end cover 5 a is a circular aperture recessedfor receipt of the bearing 14. The bearing 14 thus act as end supportfor the rotor 2.

FIG. 3 shows the same as FIG. 2, except that the end bearing 14 islifted off the end of the rotor 2. Thus more of the rotor 2 isappearing.

FIG. 4 shows the same as FIG. 3, but where another plate 5 b of thehousing 5 is lifted off. Thus more of the rotor 2 appears and shows arotor vane 1 a. Also the inlet passage 3 is shown. The inlet passage 3leads from the external of the engine housing 5 to a chamber 9 a withinthe housing 5. That part of the rotor 2 having the vanes 1 a and thehousing part 5 c that is illustrated in FIG. 4, constitutes a firstcompressor unit that rotates around the axis A.

In FIG. 5 is another part 5 c of the housing 5 lifted off and furtherparts of the rotor 2 appear. Thus a rotor vane 1 b is shown that runs inthe chamber 9 b and together with this part of the rotor 2 forms thecombustion engine unit. From the chamber 9 b in the combustion engineunit an outlet passage 4 is extending and leads to the environment.

In FIG. 6 is another plate part 5 d of the housing 5 lifted off and moreof the combustion engine unit appears.

In FIG. 7 is the upper half 2 a of the rotor 2 lifted off and the vaneunit 1 with its respective vanes 1 a,1 b appears clearly. The vane unit1 comprises in the shown embodiment three compressor vanes 1 a and threecombustion engine vanes 1 b. Each vane 1 a,1 b is articulated connectedto one end of a control arm 7 which is in the other end thereofpivotally supported in a stationary axle shaft 8 having a central axis Bcoincident with the longitudinal axis of the engine housing 5. This isshown in entirety in FIG. 8-12. The control arms 7 do not transmit anypower, but provide for that each vane 1 a,1 b,1 c are in forced motionto slide radially inwardly and outwardly in guide slots 11 in the rotor2 so that the vane tips at any time during the rotation of the rotor 2are tangent to the internal surfaces of the housing. The referencenumber 6 denotes an eccentric adapter which is further described laterwith reference to FIG. 22. The other compressor unit is lying under thecombustion engine unit and is completely corresponding to the uppercompressor unit.

In FIG. 8 is the lower part 2 b of the rotor 2 shown after the vane unit1 is lifted off. In this figure the radially extending slots 11, whichthe respective vanes 1 a, 1 b, 1 c are running in, are clearly shown. Asmentioned, the axle shaft 8 is centrally extending in the cavity 9 ofthe housing 5. The axis A of the rotor 2 extends in parallel with thecentral axis B of the housing 5, but is extending eccentric in respectof the axis B of the housing 5. This eccentricity is illustrated in FIG.7 where both axis A and B are shown. By means of this eccentricity theradial movement is obtained, or the forced movement of the respectivevanes 1 a,1 b,1 c inwardly and outwardly in the respective guiding slots11 in the rotor 2.

FIG. 9 shows the cavity 9 in the engine housing 5 after that also thelower part 2 b of the rotor 2 is lifted out.

In FIG. 10 is still another plate part 5 e of the housing lifted off.

FIG. 11 shows the final end cover 5 g after the plate part 5 f is liftedoff.

FIG. 12 shows the stationary axle shaft 8 fixed to a stationary endflange 15.

FIG. 13 shows the vane unit 1 as assembled when it is to be put on thestationary axle shaft 8. As mentioned, the vane unit 1 consists of acombustion engine vane 1 b and two compressor engine vanes 1 a and 1 clocated on each side of the combustion engine vane 1 b. Each set ofvanes 1 a,1 b,1 c is articulated connected to respective control arms 7.When the vane unit 1 consists of three set of vanes, it is found to beconvenient to arrange the respective control arms 7 with differentmutual distance for each set of vanes 1 a,1 b,1 c as shown in FIG. 14.Each control arm 7 includes a bearing 16 that enables the set of vanes 1a,1 b,1 c and each control arm 7 to rotate around the stationary axleshaft 8. Further, each set of vanes consists of an articulatedconnection in form of an axle pin 17, having rotational axis C, that isprovided between the set of vanes 1 a,1 b,1 c and two control arms 7.

It is further to be understood that in a presently considered optimalembodiment of the engine, there is a certain relation between thethickness t of each vane, the distance between the axis C and the axis Band the eccentricity of the rotor 2 in respect of the housing 5, i.e.the distance between the axis A and B. This is necessary in order thatthe vane tips 1 bt are to follow, with predetermined distance andminimum clearance, the internal surface 20 of the housing 5. Further,the surface of the vane tips 1 bt have to be arcuate such that thesurface continuously follows or is tangent to the internal surface 20 ofthe housing 5 with small clearance. The point of tangent is, however,displaced along the arcuate surface of the vane tip 1 bt and isperforming like a rocking movement on the internal surface 20. In orderto get this to correspond, do the surface of the vane tips 1 bt have acentre of curvature in the axis C that links the vane 1 b to the controlarm 7. This is easier understood by studying FIGS. 19-21. The samerelation as the above described is also true for the compressor vanes 1a and 1 c having their own thickness, separate distances and curvatureof the vane tips.

The surfaces of the vane tips might be provided with a suitable sealingmeans for engaging the internal surface 20 of the housing 5. It is,however, most preferred that no contact occur between these surfaces andthus can a suitable solution comprise labyrinth sealings on the surfaceof the vane tips in necessary extent and design.

FIG. 15 shows the upper part 2 a of the rotor 2 and which constitute thehub for power output, while FIG. 16 shows the same part inverted so thatthe internal cavity and the guiding slots 11 a that the upper compressorvanes 1 a are sliding radially in and out of, can be seen.

FIG. 17 shows the lower part 2 b of the rotor housing 2 viewedinternally and FIG. 18 shows the same part viewed externally and withthe respective sliding slots 1 b for the combustion engine vanes 1 b andsliding slots 1 c for the vanes 1 c on the lower compressor unit.

The operation of the engine will now be described and is given withreference to FIGS. 4-6. As indicated earlier, the illustrated embodimentof the invention shows a combustion engine having a compressor unit oneach side. The rotor 2 will be rotating about its centre axis A in thedirection that the arrow R indicates in FIG. 4. When the rotor 2rotates, the compressor vanes 1 a, which are running in the compressorchamber 9 b, draws an air/fuel mixture through the passage 3 and intothe chamber 9 b. The suction period starts when the vane 1 a is passingthe inlet of passage 3 leading into the chamber 9 b and lasts till thenext vane passes the same inlet. That side of the compressor vane 1 a,which faces opposite of the sense of rotation, constitutes the suctionside of the compressor, while that side which faces in the sense ofrotation constitute the pressure side. This implies that when thecompressor vanes 1 a pass the inlet of passages 3 to the chamber 9 a,the pressure side of the compressor vane 1 a commences its compressionwork, while the opposite side commences its suction work. Because thechamber 9 a taper in that the internal surface 20 of the housingconverge toward the peripheral surface 21 of the rotor, a compressingoperation is achieved in known manner when the vanes 1 a are displacedin the chamber 9 a.

Further, passages are provided between the compressor chamber 9 a andthe combustion chamber 9 b in the combustion engine unit locatedadjacent to the compressor unit in the next “layer”, as disclosed inFIGS. 5 and 6. Each passage extend from the most narrow part of thecompressor chamber 9 a and opens into the combustion chamber 9 b wherethe chamber starts to widen out and forms together with the vanes 9 b anexpansion chamber. The passage or passages can be located at suitableplaces, like in the body of the engine housing 5 or in the rotor withthe rotor vanes 1 a,1 b acting as valves for letting in the fuel mixtureat correct moment. In FIG. 6 is the outlet of the passage from the lowercompression chamber 9 c into the combustion chamber 9 b denoted by thereference number 12. A corresponding outlet is provided through thehousing 5 from the upper compression chamber 9 a, but that is not shownin the drawings. The outlets do, however, communicate with smallerrecesses 18 in the rotor 2 for instantaneous transfer of pressure fromthe compression chamber 9 a to the combustion chamber 9 b. Thus theoutlets 12 and the recesses act like valves in respect of each other.

The fuel mixture is ignited approximately in the area in which therecess 18 is in FIG. 6 and occurs when the vane 1 b is approaching thisplace. When the rotor 2 and the vanes 1 b have passed through a certaincircle arch corresponding to the expansion phase, the passage 4 forexhaust is exposed and the exhaust is released to the environment.

As it is to be understood, the air-fuel mixture is supplied to thecombustion engine unit from both sides, i.e. from both the upper andlower compressor unit. In further embodiments, there might be onecompressor unit only, an externally compressor unit or be completelyomitted. The number of sets of vanes may vary in accordance with what isconsidered to be suitable for the respective application.

FIG. 19 shows a four vane compressor embodiment of the presentinvention. Like in the embodiment just described, this includes aschematically illustrated housing 5, a rotor 2, but four vanes 1 thatare moving radially outwardly and inwardly in sliding slots 11 recessedin the rotor 2. The housing 5 has a cavity 9 having centre in the axis Band an internal surface 20 which the end surfaces of the vanes 1 nearlytouch.

The rotor 2 has an external peripheral surface 21 and rotates about therotor axis A. Between the position C and D is the internal surface 20 ofthe housing 5 described by a cylinder surface sector correspondingsubstantially to a sector of the peripheral surface 21 of the rotor 2.Thus the complete internal surface of the housing can be described as ifit was formed of two incomplete cylinder surfaces, or cylinder surfacesectors, not having coinciding centre axis and where the smallercylinder surface cuts into the larger cylinder surface across apredetermined cylinder sector.

That location (C and D) where the two cylinder surfaces intersect, atype of valves are formed that effectively stop back flow of gases.Optionally, labyrinth sealings can be provided in the housing 5 in thearea at C and D, possibly in the entire area between C and D. Thedistance between C and D can be varied or optimised for the respectiveapplication of the machine. When the distance between C and D is zero,the internal surface of the housing 5 will be cylindrical and theperipheral surface 21 of the rotor 2 will be tangent to the internalsurface 20 along a line at the location C,D.

When the rotor 2 rotates in the direction of the arrow R, air is suckedin through the inlet passage I. The next following vane 1 carries thedrawn air with and commence compression work when the vane 1 is passingits lowermost position (six o'clock in FIG. 19). The air is compressedagainst the outlet passage U by the further movement of the vane 1towards the uppermost position (twelve o'clock in FIG. 19).

FIG. 20 shows a simple four vane rotary machine, here in form of a purepump or compressor. The machine is much similar to the compressordescribed above with reference to FIG. 19. However, just theeccentricity and those circles (cylinder surfaces) which intersect eachother appear more clearly. The rotor 2 moves in the direction of thearrow R. Air is sucked in through the inlet passage I. The air is drawnand entailed by the vanes and is displaced out again through the outletU.

FIG. 21 shows a one vane rotary machine, here in form of a pump, orcompressor unit where also optional sealing means 23 and bearings 22 areillustrated. The sealing means can be pure scraping seals or labyrinthseals. The bearing 22 can be an insert of suitable bearing material,like babbit metal or bronze, possibly teflon for some applications. Thetip of the vane can also be provided with a seal 24 that contacts ordrag against the internal surface 20′ of the housing. Between the inlet1 and the outlet U is advantageously a sealing 28 provided, preferably alabyrinth sealing.

A one vane rotary machine needs counter weights (not shown) in order tobalance mass forces. This FIG. 21 illustrates in particular thegeometric relations that apply for an optimal machine. An optimalmachine is defined as a machine having a minimum of necessary draggingor engaging seals and preferably totally omit contacting seals.Non-contacting seals, like labyrinth seals, are however acceptable.

Each vane tip describes a cylinder surface sector having a particulararch length and curvature, which are determined on basis of geometricrelations. The radius of curvature R4 of the vane tip is determined bythe distance from the axis C to the internal surface 20′ of the housing5. The thickness t of the vane, and thus the arch length of the cylindersurface, is determined by the distance between the centre axis B and theaxis C. accordingly the pivot radius R3 for the axis C, and the distanced between the rotor axis A and the centre axis B.

As it appears from the figure, see also the dotted vane in straight downposition, the tip of the vane do perform a “rolling or rocking movement”against the internal surface 20′ of the housing 5 during its revolutionwith the rotor 2. By half a revolution of the rotor 2, the vane tip hasperformed a rolling movement between the extreme edges of the arch. Thusthe vane tip is rocking back and forth once during one revolution of therotor. The vane thickness t may per se be thicker than the optimumwithout being of serious significance. If it is thinner, however, thetip of the vane will no longer at all times be tangent to the internalsurface 20′ during a revolution of the rotor and accordingly providedistance and gap between the surface 20′ and the vane tip.

FIG. 22 shows in more detail the eccentric adapter 6. The eccentricadapter 6 is non rotatable fixed to the axle shaft 8 via a key 25. Theadapter 6 have an eccentric, in respect of the centre axis B, andcylindric bearing pin 26 which supports a bearing 27 that is eccentriclocated in respect of the centre axis B, but is centric located inrespect of the rotor axis A. The bearing 27 is stabilising the axleshaft 8 in the free end thereof, in addition to provide internal supportto the upper rotor part 2 a. The bearing is accordingly concentriclocated in respect of the upper, external bearing 14 and a correspondingbearing (not shown) in the opposite end of the rotor 2, i.e. supportsthe rotor part 2 b. This eccentricity provides the forced movement ofthe vanes 1 via the control arms 7.

What is claimed is:
 1. A rotary-piston machine (10) comprising a housing(5) having a cavity (9). a rotor (2) received in the housing (5), whichrotor (2) has a rotor axis (A) and a peripheral surface (21). inlet andoutlet passages (3,4) in communication with said cavity (9), one or morevanes (1) that are radially slideable received in slots (11) in therotor (2), each vane (1) extending radially from the internal surface(20) of the housing (5) to the rotor axis (A), at least one workingchamber (9 a) being part of the cavity (9) and defined by the internalsurface (20) of the housing (5), the peripheral surface (21) of therotor (2) and the side surface of at least one vane (1), each vane (1)being articulated connected about aa axis (C) to one end of a controlarm (7) and in the other end thereof bein, pivotally supported in afixed axle shaft (8) having a central axis (B) being coincident with theaxis extending centrally through the cavity (9) of the housing (5),which axis (B) extend in parallel with and spaced apart (d) from therotor axis (A), and the rotor (2) proper constitute the unit for powertake off or power input, characterised in that each vane tip (1 bt)describes a cylinder surface sector having centre of curvature in theaxis (C) extending through the joint that connects the vane (1) to thecontrol arm (7).
 2. A rotary-piston machine (10) according to claim 1,characterised in that the arch length of the cylinder surface sector,and thus the thickness (t) of each vane, is determined of geometricrelations, i.e. the radius of curvature R4) for the cylinder surfacesector, the distance (R3) between the centre axis (B) of the cavity andthe axis (C) and the distance (d) between the rotor axis (A) and thecentre axis (B).
 3. A rotary-piston machine (10) according to claim 1,characterised in that sealing means is provided between the vane tip andthe internal surface (20) of the housing (5).
 4. A rotary-piston machine(10) according to claim 1, characterised in that sealing means areprovided between the vane slots (11) and at least one of the sidesurfaces of the vanes (1).
 5. A rotary-piston machine (10) according toclaim 1, characterised in that sealing means are provided between theinternal surface (20) of the housing (5) and the peripheral surface (21)of the rotor (2) where the surfaces are tangent to each other.
 6. Arotary-piston machine (10) according to claim 1, characterised in thatthe vane slots (11) comprises sliding bearings that coact with the vane(1).
 7. A rotary-piston machine (10) according to claim 1, characterisedin that the peripheral surface (21) of the rotor (2) across a sector(C-D) do intersect into the internal surface (20) of the housing (5) anda corresponding recess is formed in the internal surface (20) of themachine housing (5) (FIG. 19A).
 8. A rotary-piston machine (10)according to claim 1, characterised in that the machine comprises atleast one compressor unit that is co-rotating with and is correspondingto the combustion engine unit and has a separate chamber (9 a), aseparate rotor and separate vanes (1 a), and passages (12) that connectthe respective cavities (9 a,9 b,9 c).
 9. A rotary-piston machine (10)according to claim 1, characterised in that the fixed axle shaft (8) issupported and stabilised in the free end thereof by the rotor (2) bymeans of an eccentric adapter (6).